I unlocked the Sacrifice ability of my Witch Doctor a few days, but I haven't used it at all because I don't understand how to use it effectively. When dealing with a throng of enemies, I'd prefer to keep my minions around and dole out damage rather than blow my dogs up and leave me to myself. I'd prefer not to wait for 60 seconds for the cooldown period so I can summon another pack of Zombie Dogs.

In what situations is Sacrifice worth using and what other skills should I be considering in using this particular one?

Summon Gargantuan with Restless Giant (enrages at bosses)
Left Click. Firebomb with Fire Pit (creates a pool of fire that does damage over time)
Right Click. Grasp of the Dead with Death is Life (5% chance of leaving a health globe)

With regard to strategy, the Gargantuan is a tank and the Restless Giant is awesome against powerful enemies. The Zombie Handler passive gives him more health. Also, the Pierce the Veil passive is great for this build because mana is not an issue for the skills and the increased damage is helpful.

Step 1: Try to enter a fight with Zombie Dogs in tow. This isn't a must, but the build is centered around a mass Sacrifice attack. (If you don't have any dogs, skip to step 4 until cooldown is done.) Run into the thick of the enemies and use Soul Harvest (try to harvest 5 souls for the +50% intelligence bonus). Your dogs will follow you into the pack and you will have a pretty good spread. Use sacrifice. If you get a good Soul Harvest, nothing in the blast radius should survive.

Step 2: With the Next of Kin and Final Gift runes, the explosion should have left some health globes and a zombie dog or 2 should have resurrected out of the rubble. Collect all of the health globes while your 2nd wave of dogs engages the surviving enemies. Since you are using Gruesome Feast, each health globe gives you +10% intelligence. If you got a Soul Harvest of 5 and you collect 5 globes, you will now have +100% intelligence (most likely you will have +70%–80% since you won't always get a good Soul Harvest or 5 globes). Detonate the 2nd wave of dogs that resurrected from the first blast.

Step 3: Pick up the health globes from the second detonation, and repeat Step 2 if any more dogs resurrected.

Step 4: Once you are out of dogs, use Grasp of the Dead on the survivors and start firebombing them. With the +100% intelligence bonus, you will do massive damage. Pick up any health globes left behind because the +10% intelligence bonus from Gruesome Feast only lasts 10 seconds.

Step 5: Kite any survivors with Grasp of the Dead and Firebomb. Hopefully your Gargantuan will help you here. Resurrect your dogs as soon as you can and repeat step 1.

With regard to gear, I build for (1) intelligence, (2) vitality, (3) increase health from globes, and (4) increase range on health globe pickup. With a high vitality and Gruesome Feast, health globes become a valuable commodity.

Finally, I like the extended duration on Soul Harvest in case you get a bad one. The cool down on Soul Harvest is 15, so if you only get 1 or 2 you can re-harvest after 15. But if you get a good one (4 or 5), it will last for a full 60 seconds (coincidentally, the cooldown of Summon Zombie Dog).

Like I said I am level 58 and I am in Act 3 Hell and this strategy still works very well. When I solo I use the Templar.

Interesting that no one mentioned the 0-second cooldown summon & sacrifice build. With a set of items (Homunkulus, SOJ, Skull Grasp, possibly Visage of Giyua) and the 25% cooldown reduce passive, you can get a zombie dog spamming build, which is by some praised as the the highest dps build there is (yea yea, we keep hearing that one). Additionally, you can rune the dogs to produce humongous amounts of health globes in longer lasting fights (mp10 infernal machines). When you can detonate 4 dogs once a second, and each dog has 15% chance to drop a health glove then you produce 6 globes per 10 seconds!

+1 Zero dog builds are indeed very powerful (and, last I checked, very expensive!). Thanks for adding this; the builds weren't possible when the question was originally asked, as Homunculous didn't exist then.
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BeofettFeb 5 '13 at 14:08

zdogs though are still not feasible for soloing as you have to be standing still to do dps. They are great for team fights though, because of the generation of health globes. Wizards with the arcane power on health globe pickup can do some crazy things when paired up with a zdog WD.
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z 'Feb 5 '13 at 14:10

My answer is a bit outdated, as it does not address changes since higher MP levels were added. I am adding information for higher level play to update it.

For lower level play (< 60):

Sacrifice becomes much more effective when combine with additional abilities designed to give you more zombie dogs.

The Next of Kin rune for Sacrifice is a big help for sacrifice builds, giving you an excellent (35% per dog) of getting new dogs after a sacrifice.

The Devolution rune on Confusion effectively gives you a second zombie dog cool down timer, as any enemy killed while confused has a 50% chance of spawning a new zombie dog (up to your maximum number of 3, or 4 if you have the Zombie Handler passive).

Sacrifice does a lot of damage, particularly with the Pierce the Shroud passive and Soul Harvest. With 3 (or better yet, 4 with Zombie Handler) dogs exploding at once, you will clear out most normal groups, and do enough damage to champion packs that they should be easy enough to clean up.

With good Next of Kin procs, and possibly a mid-combat resummon, I found it to be a very effective tactic in early Nightmare.

Charge the group, Soul Harvest, Sacrifice, repeat Sacrifice until either the group is cleared or you are out of dogs, then resummon (and repeat if it's a champion pack or unique that is still up). Cast Confusion on a group of normalsif you need more dogs and Zombie Dogs is still on cool down.

However, it is difficult to concentrate your dogs on one target, is a bit too reliant on luck and long cool downs, and is useless against a number of bosses.

For higher levels of play (level 60, MP1+... MP level depending upon gear):

Sacrifice can become an effective way of replenishing your mana at higher MP levels, although its effectiveness will likely fall short of full MP10 play unless you are exceptionally well geared.

Once you are farming higher MP levels, Gruesome Feast and Grave Injustice become incredibly effective for maintaining a constant farming pace. Grave Injustice has an additional synergistic effect with all high-cooldown skills, including Summon Zombie Dogs.

This makes Sacrifice->Pride an effective backup for when you run out of mana, particularly on elite packs and bosses. The reduction in cooldown from GI means that it is fairly easy to keep dogs up at all times for anything other than a boss battle.

During elite fights where I am not able to quickly burn the pack down, I rely on Big Bad Voodoo -> Rain Dance, or Sacrifice -> Pride, to recharge my mana mid-fight.

Adding the Final Gift rune to your Zombie Dogs provides some small synergy with Gruesome Feast, extending the benefit of surviving those longer fights.

During non-elite battles, you should be blasting through packs of minions so fast that your timers for BBV and ZD will reset in between almost every elite pack (the exception being a few areas exceptionally dense in elite packs, such as Vault of the Assassin). To maximize the effectiveness of this, high damage skills that should one-shot packs (or at least come close to it) such as Zombie Charger -> Zombie Bears and Soul Harvest -> Vengeful Spirit are recommended.

The only time I really found a Zombie Dog Sacrifice build to work is with a heavy AoE build. I tested out the this build a little bit in Hell Act 3 and it seemed to work decently enough.

The general strategy for this is to keep Summon Zombie Dogs, Grasp of the Dead, Soul Harvest, and Summon Gargantuan on cooldown 100% of the time. Summon Dogs and Sacrifice them for AoE damage, Grasp of the Dead with improved snare to hold enemies in place, Soul Harvest for Mana regains and INT bonus, and Summon Gargantuan with AoE Stun rune. When no dogs are up and everything is on cooldown spam Zombie Bears until a Zombie Dog spawns, Sacrifice it, Repeat.

I was clearing elite packs and most mob groups decently enough with it, but I'm not sure how optimal it is. I'll have to do some more playing around with it to be sure, but it did seem viable. My only worry is how much survivability you'd have solo. With a group though this build just melts everything.

You use it when the Zombie dogs are getting ready to die. They are going down anyway so you might as well get a bang out of them. Watch the health bar and just keep an eye on how much they are getting beat and you'll learn to know when to trigger it. Ideally you want to sacrifice them when your dogs are off cooldown so that you can pop them up again. If you've already weaken the mobs with aoe, the three dogs going off can be enough to finish off the group for you.

It is also useful with Circle of Life (think that is the name) passive that spawns extra zombie dogs. Though you have to be in range of the enemy getting killed for that to fire off.

Runes will allow you to either get healed by the sacrifice or possibly even respawn a dog. The skill will make more sense when you start to get those runes and better dogs.